PSR-4 not loading my project classes - php

Question

I'm using Composer's PSR-4 to autoload classes, but it won't load my classes.
Every time I try to use one of my classes the app dies without any error, even though it should display error.
Here is my file structure:
/
│ composer.lock
│ composer.json
│ index.php
├───src
│ Array.php
│ File.php
├───vendor
...
composer.json - autoload part
"autoload": {
"psr-4": {
"FileManager\\": "src"
}
}
Start of index.php
<?php
require(__DIR__ . '/vendor/autoload.php');
var_dump(class_exists('Array'), class_exists('Array', false));
var_dump(class_exists('File'), class_exists('File', false));
And it dumps this:
bool(false)
bool(false)
bool(false)
bool(false)
If I add
use FileManager\Array;
it will die instantly. If I add
use FileManager\File;
it won't die, but it won't recognize File class either.
I have ran
$ composer dumpautoload
Can somebody help me with this?

Answer 1

The problem is that you are passing strings to class_exists().
If you use string values to reference class names, you will need to use the fully-qualified class name.
<?php
require_once __DIR__ . '/vendor/autoload.php';
var_dump(
class_exists('FileManager\ArrayUtil'),
class_exists('FileManager\File')
);
Alternatively, you can use the class keyword (requires at least PHP 5.5):
<?php
use FileManager\ArrayUtil;
use FileManager\File;
require_once __DIR__ . '/vendor/autoload.php';
var_dump(
class_exists(ArrayUtil::class),
class_exists(File::class)
);
For reference, see:
http://php.net/manual/en/language.namespaces.dynamic.php
http://php.net/manual/de/migration55.new-features.php#migration55.new-features.class-name
http://php.net/manual/en/language.oop5.basic.php#language.oop5.basic.class.class